What is one requirement for the 1000m swim event?

The requirement for the 1000m swim event that swimmers must touch the wall at every turning point is fundamental for ensuring that swimmers complete the event correctly and adhere to the rules of competitive swimming. Touching the wall not only signifies the completion of a lap but also allows swimmers to accurately measure their overall distance and transition effectively between strokes. This requirement is common across various swimming events to maintain consistency and fairness.

Additionally, while other options may present specific conditions for swimming, the primary purpose of requiring swimmers to touch the wall is to ensure they are following established swimming protocols. As for aspects like swimwear, use of goggles, and the ability to rest during the swim, these factors do not hold the same critical importance when it comes to measuring performance and technique within the context of the event. Touching the wall is a clear directive essential for proper performance in the 1000m swim event.